Cooling-water supply apparatus for compressors



Jan. 4, 1949. c. w. METZGAR 2,453,234

COOLING-WATER SUPPLY APPARATUS FOR COMPRESSORQ Filed Feb. 16, 1945 K J1 NV ENTOR H f2. I ll lyllletffgazr'.

HIS ATTORNEY;

Patented Jan. 4, 1949 COOLING-WATER SUPPLY APPARATUS FOR COMPRESSORS Chester W. Metzgar, Easton, Pa, assignor to Ingersoll-Rand Company, New York, N. Y., a corporation of New Jersey Application February 16, 1945, Serial No. 578,318

Claims.

1 This invention relates to air compressors, and more particularly to a cooling-water supply apparatus for compressors of the multi-stage type having intercoolers to reduce the temperature of the compressed fluid between stages of compres- One object of the invention is to assure an eco nomical use of the cooling water delivered to the various water cooled portions of the compressor apparatus.

- A more specific object is to vary the supply of cooling water in accordance with the variations in the load of the compressor,

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings accompanying this specification and in which similar reference numerals refer to similar parts, Figure 1 is an elevation, partly broken away, of a multi-stage compressor and an intercooler. therefor equipped with cooling-water supply apparatus constructed in accordance with the practice of the invention,

Figure 2 is a side elevation of the compressor as viewed from the left hand side of Figure 1, and Figure 3 is an enlarged view, in elevation, partly broken away, of a detail.

Referring more particularly to the drawings,

the compressor apparatus, designated in general by 26, comprises low and high pressure cylinders 21 and 22 and an intercooler 23 seated upon the cylinders for conveying compressed fluid from the low to the high pressure cylinder and to reduce the temperature of such fluid. The intercooler 23 is shown as being of'the type forming the subject matter of my United States Patent 1,868,639 and, as is therein explained, comprises a casing 24 that serves as a conduit between the discharge opening of the low pressure cylinder and the inlet opening of the high pressure cylinder. The casing contains a pair of cooling units 25 and 26 that are inserted through the opposite ends of the casing and suitably positioned to communicate with water heads 2? and 28, respectively, at the ends of the casing 24.

The cylinders 2| and 22, as is customary, are arranged at the crank ends of bed plates 29 and are supported by standards 30 resting upon base plates 31 for the bed plates 29, and the cylinders 2i and 22 and their end closures are suitably chambered to form therein water jackets 32 and 33, respectively.

The cylinders are provided with the usual heads and valve mechanisms therein for controlling the admission of air into and the discharge of compressed air from the cylinders. Thus, the low pressure cylinder 2! has a head 34 at its outer end, and a head 35 is interposed between the other end of the cylinder and its bed plate. The valve mechanisms hereinbefore referred to are not illustrated since they may be of any well known type, but their positions are indicated by plates serving as covers for'the recesses accommodatin them, the plates being designated 36 and 3'? accordingly as they are associated with an inlet valve or a discharge valve.

Similarly, the low pressure cylinder has a head I 38 at its outer end and a head 39 at its crank end, and these heads also contain suitable inlet and discharge valve mechanisms the positions of which are indicated by the plates 36 and 3?.

The compressor is, moreover, provided with devices for regulating its load in step-by-step fashion. These devices may also be of a well known type and are shown as consisting of clearance valve mechanisms 40, two being shown arranged in each cylinder head. They are located in diametrically opposite sides of the heads and comprise, as is more particularly shown in Figure 1 of the drawings, a cage- 4| threaded into the outer wall of the head and containing a differential piston 42 the smaller end 43 of which serves as a valve and controls a port 44 affording communication between the cylinder and a clearance pocket 45 in the head. The outer, enlarged end of the piston 42 constitutes a pressure surface 46 that is subjected to pressure fluid for holding the piston normally in position to seal the port 44.

The flow of pressure fluid to and from the pressure surfaces 46 is controlled by a regulator 41 of the type forming the subject matter of my United States Patent 1,430,478 to which reference may be had for a full and clear description of the arrangement of its parts and the mode of operation. It may be here briefly stated, however, that the regulator 4! is responsive to the pressure of the final discharge output of the compressor and operates in such wise that, at predetermined values in the discharge output of the compressor, it effects the valving of pressure fluid to and from the clearance Valves.

In the arrangement shown the clearance valves are intended to be operated in pairs to efiect the loading and unloading of the compressor in steps of one-quarter load. One clearance valve at one end of the low pressure cylinder and a clearance valve at the opposite end of the high pressure cylinder are accordingly connected by a common conduit in order to effect their simultaneous oper- 3 ation. More specifically, one clearance valve 40 in the outermost head 34 of the low pressure cylinder 2| and a clearance valve in the head 39 at the crank end of the high pressure cylinder 22 are connected by a conduit 48 leading from the regulator 41.

In like manner, a clearance valve 4% in the head 35 at the crank end of the low pressure cylinder and a clearance valve in the head 38 of the high pressure cylinder are in communica-' tion with each other through a common conduit 49 that is also connected to the regulator 41. The remaining clearance valves may be connected in pairs in the manner described and to the regulator 47 by conduits similar to those designated 48 and 49.

In the arrangement shown, the first step of unloading may be effected by exhausting the pressure fluid from the pressure surfaces of the clearance valves connected to the conduit 48. These clearance valves will then be unseated by the compressed fluid acting against thesmallends 43 of the pistons 42 and theiarea of the associated clearance pockets will thereby be communicated with the cylinders to partly unload the compressor. 1

In' the event that the terminal pressure of the compressed fluid is again reached the regulator 41, responding thereto, will effect the exhaust of pressure fluid from another pair of clearance valves, say those connected to the conduit 49. These valves will then open and furtherreduce the load of the compressor. In like manner, other pairs of clearance valves may be caused to operate for effectin additional steps of unloading of the compressor whenever the discharge output again reaches the terminal pressure. I If, on the other hand, the value of the pressure of the discharge output should fall to a predetermined value the regulator 4-7 will valve pressure fluid to the clearance valves in pairs and move them to their sealing positions on the ports 44, thereby applying a step, or steps, of loading to the compressor.

In. accordance with the practice of the invention, it is contemplated to vary the supply of cooling water to the water jackets and the intercooler and in synchronism With the steps of application or reduction of the load in order to minimize the cost of operation of the compressor. In a preferred arrangement of the invention the cooling water is first circulated through the intercooler, thence delivered to the water jackets 3'2 and The supply conduit 50 leadingfrom a suitable source of Water is accordingly connected to the head 27 of the intercooler to deliver the Water first to the cooling unit 25, and a conduit 5i extending from the head 2'! to the head 28 next delivers such water to the cooling unit 26. The water next passes from the head. 28 through asdischarge conduit 52 to the water jackets 32 and 3 The supply conduit 58' is provided with a valve 4 I the casing, respectively, so that the branch 59 opens into the chamber 51 and the branch 60 communicates with the chamber 58.

Communication is afforded between the chambers 5'! and 58 through a group of ports 6|, 62 and 63 in the wall 51. The ports 62 and 63 are of larger fi owarea thanthe port G l which is open constantly to permit water to .fiow constantly from the chamber 5'! to the chamber 58. The

.ports 62 and 63, on the other hand, are controlled terposed between the valves and plugs 51 threaded into the lower wall of. the casing.

Each. valve. has a. depending stem 68 that extends slidablyinto a bore 69 in the inner end of 53 for manually controlling the supply of water connected to the lower wall and to a sidewall of the plug 5? to guide the lower ends of the valve members, and in the plug 6'! are screws 10 that extend into the bores 69 to limit the extent of unseating movement of the valves. The valves 64 and 6-5. are unseated by pressure fluid toop-en the ports 62 and B3, and each valve has a stem 1 lextending through the associated portand carrying a head 12 that slides in a bore 1-3- in the upper wall 14' of the casing 515 to assist-in guiding. the valve.

The wall. 14 also supports a pair of cover plates 15 that may be secured to the casing v55: many convenient manner and. are suitablycontoured to define pressure chambers 16 and 1'! .over the heads 12 of: the valves 54- and 65, respectively.

Preferably, flexible diaphragms. 1a overlie the head 72 and are clamped between the cover plates t5 and the casing 55 to seal the chambers'lfir-and 11 Y In order to effect the ow of pressure fluid into and from thechambers l5 and 11; in synchronisintype-and is suitably biased toassure aiull volume r of water in the water jackets.

Each cylinder also has the usual. drain pipe 53" carrying an overflow belt 84' through which the extent-of overflow may beobserved, and valves .85 are interposedin the'discharge conduit 52' to regulatethe'supply of water for the water jackets in accordance with the. variations in temperature and moisture content of: the, fluid: being compressed. The valves 85 are manually operable a readjusted; as required', to assure the degree of circulation of water through the water jackets best suited to maintain the correct'temperature conditions inthe cylinders.

'In operation,,-let .it be assumed that the com-i- :pressor is fully loaded: and. that the regulator -41 then operates to maintain. pressure fluid .in the.

clearance valve mechanisms for holding the: pie

tons 42 in position. to seal the ports 44. Pressure fluid will then also "act. against the heads: 1:2:a-nd hold the valves 64 and 65' open. Withthe'se parts "in the positions described, the fluid charged from the low pressure cylinder 24'. will flow .throughsthe intercooler to the high pressure cylinder 22 wherein it is compressed. torahigher value. I

At the-same time a fullsupply of water'will' flow from the chamber 51' through the ports 6|, 62 and 63 into the chamber 58, thence through the cooling unit 25 and the conduit to the cooling unit 26. After passing through the cooling unit 26 the Water flows through the discharge conduit 52 into the cooling jackets 32 and 33, thence from the water jackets through the overflow pipes 83. Any water flowing from the cooling unit 26 in excess of the requirements of the water jackets will be discharged from the stand-pipe 8|.

The clearance valves and the valves 64 and 65 will remain in these positions until the pressure of the compressed fluid reaches the predetermined maximum value and the regulator will then act to exhaust pressure fluid from a pair of clearance valves to communicate the associated clearance chambers with the adjacent ends of the compressor cylinders. Upon the discharge of pressure fluid from the clearance valves, say those associated with the conduit 48, the pressure fluid is simultaneously exhausted from the chamber 77 and the valve 64 will then be pressed into sealing relation with the port 62 by the spring 66, thereby reducing the flow of water from the chamber 5'! to the chamber 58. Thereafter, water will flow only through the ports GI and 63 to the intercooler and the water jackets.

If, during the subsequent operation of the compressor, the predetermined maximum value of the discharge output of the compressor is again reached the regulator 41 will operate to efiect another step of unloading. This, in the example shown, would consist in exhausting the pressure fluid from the clearance valves connected with the conduit 39. At the same time the pressure fluid is exhausted from the chamber '16 and the valve 55 is moved to its closed position by its spring 66. The compressor will then operate at half load and only the water that may pass through the constantly open port 6! from the chamber 57 into the chamber 58 will be delivered to the intercooler and to th water jackets.

Conversely, whenever the pressure of the discharge output of the compressor drops to the predetermined minimum value at which the regulator 47 and the clearance valves will operate to apply steps of loading to the compressor, pressure fluid will simultaneously be admitted into the chambers 16 and T! for unseating the valves 65 and 64. In this way the supply of water to the water cooled parts of the compressor apparatus will be augmented in accordance with requirements.

I claim:

1. In a cooling-water supply apparatus for a compressor, in combination, a cylinder having a water jacket, means for supplying water to the water jacket, means for effecting the partial unloading and reloading of the cylinder, and means acting in synchronism with the second said means for decreasing and increasing the supply of water to the water jacket in accordance with the reduction and the increase in the load of the cylinder.

2. In a cooling-water supply apparatus for a compressor, in combination, a cylinder having a, water jacket, means for efiecting the partial unloading and reloading of the cylinder, means acting in synchronism with the first said means for decreasing and increasing the supply of cooling water to the water jacket in accordance with the reduction and the increase in the load of the cylinder, and a controlling means for efieoting the simultaneous operation of both means.

3. In a cooling-water supply apparatus for a compressor, in combination, a cylinder having a water jacket, means for supplying water to the water jacket, a plurality of load-controlling devices for effecting a step-by-step loading and unloading of the cylinder, and a plurality of means for controlling the flow of water to the water jacket and each of the last mentioned means acting in synchronism with a load-controlling device to effect the increase and decrease in the flow of water for the water jacket in accordance with the increase and the reduction in the load of the cylinder.

4. In a cooling-water supply apparatus for a compressor, in combination, a cylinder having a water jacket, water conveying means having a plurality of ports through which Water flows to the water jacket and one of said ports being constantly open to permit the constant flow of water to the water jacket, pressure fluid actuated means for efiecting the partial loading and unloading of the cylinder, pressure fluid actuated valve means to control another of said ports, and means for controlling the pressure fluid supply to the first mentioned means and to the valve means for causing their simultaneous operation.

5. In a cooling-water supply apparatus for a compressor, in combination, a plurality of cylinders each having a water jacket, an intercooler for the compressor, means for supplying water to the intercooler and the water jackets, means having a plurality of ports through which water flows to the intercooler and the water jackets and one of said ports being constantly open to permit the constant flow of water to the intercooler and the water jackets, pressure fluid actuated valves for controlling the other ports, pressure fluid actuated load-controlling devices for efiecting a step-by-step loading and unloading of the cylinders, and pressure responsive means for controlling the pressure fluid supply to the load-controlling devices and to the valves for causing the operation of a valve simultaneously with the operation of a load-controlling device,

CHESTER W. METZGAR.

REFERENCES oI'rEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 864,990 Richards Sept. 3, 1907 985,864 Turner Mar. 7, 1911 1,57l,758 Redfielcl May 2, 1926 1,582,028 Dunn Apr. 27, 1926 1,607,531 Haight Nov, 16, 1926 1,623,798 Limont Apr. 5, 1927 1,643,996 Raymond Oct. 4, 1927 1,707,307 Holdsworth Apr. 2, 1929 1,758,538 Redfield May 13, 1930 1.797,688 Le Valley Mar. 24, 1931 

